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Questions in chemistry

[Answered] What is the average atomic mass of the element in the data table? | Mass (amu) | Abundance (%) | | :---------- | :------------- | | 35.0 | 75.77 | | 37.0 | 24.23 | A. 63.9 amu B. 21.0 amu C. 41.2 amu D. 35.5 amu

[Answered] solid $A+$ water $\longrightarrow$ saturated solution At $60^{\circ} C 24g+100 g \rightarrow 124 g$ At $60^{\circ} C$ 100g of water is mixing 124 g solid $=30 g$ of water saturate? $\begin{array}{l} =\frac{30g \times 124g}{100g} \\ =37.2g \end{array}$

[Answered] For a certain chemical reaction, the standard Gibbs free energy of reaction is -67.5 kJ. Calculate the temperature at which the equilibrium constant [tex]K=2.8 \times 10^{12}[/tex]. Round your answer to the nearest degree.

[Answered] How many grams of nitrogen are in 3.51 mol N? [?] g N

[Answered] You have a cream containing 0.5% w/w calamine. What amount of hydrocarbon is needed such that when requested to add to this cream, it will be 70.0% w/w? What is the concentration of hydrocarbon in the new cream?

[Answered] a) What is the name for the structure of an ionic compound as shown in the diagram? ​

[Answered] Decide whether each pair of elements in the table below will form an ionic compound. If they will, write the empirical formula of the compound formed in the space provided. | element #1 | element #2 | Forms ionic compound? | empirical formula of ionic compound | |---|---|---|---| | potassium | fluorine | | | | oxygen | cesium | | | | barium | cesium | yes no | | | bromine | oxygen | yes no | |

[Answered] What's mass? A) A measure of an element's attraction for electrons B) The force that gravity exerts upon an object C) The sum of the number of protons and neutrons in an atom D) A measure of the amount of matter an object contains

[Answered] If you are measuring how water chemistry changes in a river in the days after a flood, the time measurement is the A. independent variable. B. independent constant. C. dependent variable. D. dependent constant.

[Answered] The equation for the pH of a substance is [tex]$pH =-\log \left[ H ^{+}\right]$[/tex], where [tex]$H +$[/tex] is the concentration of hydrogen ions. What is the approximate pH of a solution if the concentration of hydrogen ions is [tex]$5.0 \times 10^{-4}$[/tex] moles per liter? A. 2.7 B. 3.0 C. 3.3 D. 3.6